You cause a black aura of negative energy to form on your hand that suppresses the life force of any living creature you touch. You must make a touch attack to hit. If you hit, the subject gains 1 negative level. Assuming the subject survives, it regains the lost level after a number of minutes equal to your caster level (maximum 10 minutes). Usually, negative levels have a chance of becoming permanent, but the negative levels from languor don't last long enough to do so. An undead creature touched by the spell gains 5 temporary hit points for 1 hour.